Type Parameters:

R - see LongFunction

All Superinterfaces:

LongFunction<Optional<R>>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@FunctionalInterface
public interface OptionalLongFunction<R>
extends LongFunction<Optional<R>>
```
Variation of LongFunction that returns Optional instead of the raw value. OptionalLongFunction is typically obtained from ExceptionHandler.fromLongFunction(LongFunction), in which case its return value is empty when the underlying LongFunction throws an exception. See noexception tutorial.

See Also:

ExceptionHandler.fromLongFunction(LongFunction), LongFunction

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`Optional<R>`	`apply(long value)`	Variation of `LongFunction.apply(long)` that returns `Optional`.
`default LongFunction<R>`	`orElse(R result)`	Converts this `OptionalLongFunction` to plain `LongFunction` using default value.
`default LongFunction<R>`	`orElseGet(Supplier<R> source)`	Converts this `OptionalLongFunction` to plain `LongFunction` using fallback `Supplier`.

- Method Detail
  - apply
```
Optional<R> apply(long value)
```
    Variation of LongFunction.apply(long) that returns Optional. If this OptionalLongFunction is obtained from ExceptionHandler.fromLongFunction(LongFunction), the Optional will be empty only if the underlying LongFunction throws. Otherwise the returned Optional just wraps the return value of underlying LongFunction (possibly null).
    
    Specified by:
    
    apply in interface LongFunction<R>
    
    Parameters:
    
    value - see LongFunction.apply(long)
    
    Returns:
    
    Optional typically wrapping return value of LongFunction.apply(long), or an empty Optional (typically signifying an exception)
    
    See Also:
    
    ExceptionHandler.fromLongFunction(LongFunction), LongFunction.apply(long)
  - orElse
```
default LongFunction<R> orElse(R result)
```
    Converts this OptionalLongFunction to plain LongFunction using default value. The returned LongFunction will unwrap present value from the Optional if possible, or return result if the Optional is empty.
    
    Parameters:
    
    result - default value to return instead of an empty Optional
    
    Returns:
    
    plain LongFunction that either unwraps Optional or returns default value
    
    See Also:
    
    orElseGet(Supplier), Optional.orElse(Object)
  - orElseGet
```
default LongFunction<R> orElseGet(Supplier<R> source)
```
    Converts this OptionalLongFunction to plain LongFunction using fallback Supplier. The returned LongFunction will unwrap present value from the Optional if possible, or fall back to calling source if the Optional is empty.
    
    Parameters:
    
    source - Supplier to query for fallback value when Optional is empty
    
    Returns:
    
    plain LongFunction that either unwraps Optional or falls back to source
    
    See Also:
    
    orElse(Object), Optional.orElseGet(Supplier)

Interface OptionalLongFunction<R>

Method Summary

Method Detail

apply

orElse

orElseGet